Insecticidal phosphonothioates



3,082,148 INSECTICIDAL'PHOSPHONOTHIOATES Joseph W. Baker, Kirkwood,Peter E. Newallis, Crestwood and John P. Chup'p,Kirkwood, Mo., assignorsto Monsanto Chemical Company, St. Louis,-Mo., a corporation of DelawareN Drawing. Filed Mar. 6, 1961, Ser. No. 93,311

- 20 Claims. (Cl. 167-30) This invention relates to novel O-(aryl)phosphonothioates and to the preparation of same. Additionally thisinvention relates to insecticidal compositions containing these novelO-(aryl) phosphonothioates as an active ingredient.

The O-(aryl) phosphonothioates of this invention can be represented bythe structure ROS ; propyl, buty], amyl, hexyl, heptyl, octyl, allyl,methallyl,

ethallyl, butenyl, pentenyl, propargyl, butynyl, and the variousisomeric aryl, alkaryl, aralkyl, cycloalkyl, alkyl,

United "Statcsi. ZPatent-it alkenyl, alkynyl, etc., forms thereofcontaining up to 8 carbon atoms.

As illustrative of hydrocarbyl radicals, i.e. R, are phen-.

yl,'tolyl, xylyl, ethylphenyl, benzyl, phenethyl, cyclohexyl, 4

methylcyclohexyl, cyclopentyl, cycloheptyl, methyl, ethyl, propyl,butyl, amyl, hexyl, heptyl, octy-l, and the various isomeric aryl,alkaryl, aralkyl, cycloalkyl, alkyl, etc. forms thereof containing up to8 carbon atoms and which are free ofolefinic and acetylenicunsaturation.

- The method of this invention comprises reacting wherein m and n havethe aforedescribed, significance with wherein R and R have theaforedescribed significance and wherein Z is a halogen of atomic numberin the range of 16 to 36 (i.e. chlorine or bromine, preferably chlorine)in the presence of one ormore hydrogen halide scavenging agent.

As illustrative of the hydroxy substituted reactants of the method ofthis invention are 2-nitro-4-trifluoromethylphenol,2,6-dinitro-4-trifluorornethylphenol, 2-nitro-5- trifiuoromethylphenol,2,4-dinitro-5-trifluoromethylphenol,

.lutidine, pyridine, l-pipecoline, etc.

Ice

As illustrative of hydrogen halide scavenging agents of the method ofthis invention are sodium carbonate, potassium carbonate, thetertiaryamines such as triethylamine, tripropylamine, tributylamine,dimethylaniline, These scavenging agents will be employed ordinarily inan amount at least suflicient to absorb the hydrogen halide by-productof the reaction. They can be added at the beginning of the reaction orthroughout the course of the reaction.

Where and when desired an inert organic liquid or solvent (e.g. benzene,toluene, xylene, acetone, butanone, dioxane, etc.) can be used in themethod of this invention.

While-a wide range of reaction temperatures can be employed provided thesystem is fluid (i.e. a reaction temperature above the freezing-point ofthe system up to i and includingthe boiling point of the system) it ispre- EXAMPLE I To a suitablereaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 88 parts byweight of benzene, approximately 12.4

parts by weight (substantially 0.06 mole) of3-trifluoromethyl-4-nitrophenol, approximately 6.1 parts by weight3-nitro-S-trifluoromethylphenol, 2-nitro3-trifluoromethylphenol,3-trifluoromethyl-4-nitrophenol,.etc. Usually the hydroxy substitutedreactant will be 3-trifluoromethyl-4- nitrophenol.

As illustrative of the halide reactants of the method of this inventionare O-ethyl methylphosphonochloridothionate, O-(n-propyl)ethylphosphonochloridothionate, 0- (nbutyl)methylphosphonochloridothionate, O-methylcyclohexylphosphonobromidothionate, O-ethylbenzylphosphonobromidothionate, O-ethyl phenylphosphonc (substantially0.06 mole) of triethylamine, and approximately 9.5 parts by weight(substantially 0.06 mole) of O-ethyl methylphosphonochloridothionate.While agitating the mixture is heated up to the reflux temperature andthen refluxed for 5 hours. i The reaction mass is then cooled to roomtemperature and then quenched with water. The organic layer is separatedand washed first with aqueous 3% sodium carbonate and then with water.The so-washed solution is then stripped of volatiles under vacuum. Theresidue, an oil, is O-ethyl O-(ii-trifluoromethyl-4-nitrophenyl)methylphosphonothioate.

EXAMPLE II Employing the procedure of ExampleI but replacing O-ethylmethylphosphonochloridothionate with a substantially equimolecularamount of O-methyl ethylphosphonobromidothionate there is obtainedO-methyl O-(3- trifluoromethyl 4 nitrophenyl) ethylphosphonothioatewhich is insoluble in water.

EXAMPLE III e To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approxi' mately par-ts byweight of benzene, approximately 14.5 pants by weight (substantially0.07 mole) of 3-tri fluoromethyl-t-ni-trophenol, approximately 7.1par-ts by weight ,(substantially 0.07 mole) of triethylamine, andapproximately 14.5 parts by weight (substantially 0.07 mole) ofO-(n-butyl) methylphosphonochloridothionate.

EXAMPLE IV Empoly-ing the procedure of Example III but replacingO-(n-butyl) methylphosphonochloridothionate with an equimolecular amountof O-allyl ethylphosphonochloridothionate there is obtainedO-allylO-(3-trifluoromethyl-4-nitrophenyl) ethylphosphonothioate which iswater-insoluble.

EXAMPLE V To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 10.4 parts by weight (substantially0.05 mole) of 3-tri-' fiuoromethyl-4-nitrophenol, approximately 5.1parts by weight (substantially 0.05 mole) of triethylamine, and

" quenched with water.

4 EXAMPLE IX To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 16.8 parts by weight (substantially0.08 mole) of 3-tritfluoromethyl-4-nitrophenol, approximately 8.3 partsby weight (substantially 0.08 mole) of triethylamine, and approximately13.6 parts by weight (substantially 0.08 mole) of O-isopropylmethylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for 8 hours. The reactionmass is then cooled to room temperature and then The organic layer isseparated and washed first with aqueous'3% sodium carbonate and thenwithwarter. The so-washed solution is then stripped of volatiles undervacuum. The residue, an oil, is O-isopropylO-(3-trifluoromethyl-4-nitrophenyl) methylphosphonothioate.Analysis.-Theory: 4.1% N. Found: 4.2% N.

v EXAMPLE X Employing the procedure of Example IX but replacingO-isopropyl methylphosphonochloridothionate with an equimolecular amountof O (n-propyl) phenylphosapproximately 10.6 parts by weight(substantially 0.05 I

mole) of O-cyclohexyl methylphosphonochloridothionate. While agitatingthe mixture is heated up to the reflux temperature and then refluxed for8 hours. The reaction mass is then cooled to room temperature and thenquenched with water. The organic layer is separated and washed firstwith aqueous 3% sodium carbonate and then with water. The so-washedsolution is then stripped of volatiles under vacuum. The residue, anoil, is O-cyclohexyl O-(3-trifluoromethyl-4nitrophenyl)methylphosphonothioate. Analysis.-'Iheory: 8.0% P, 3.6 N. Found: 7.9% P,3.4% N.

EXAMPLE VI yl) methylphosphonothioate which is insoluble in water.

EXAMPLE v11 I To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 10.4 parts by weight (substantially0.05 mole) of 3-trifiuoromethyl-4-nitrophenol, approximately 5.1 partsby weight (substantially 0.05 mole) of triethylamine, and approximately10.2 parts by weight (substantially 0.05 mole) of O-(n-hexyl)methylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for 6 hours. The reactionmass is then cooled to room temperature and then quenched with water.The organic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so-washed solution is then strippedof volatiles under vacuum. The residue, an oil, is O-(nhexyl)O-(3-trifluoromethyl-4nitrophenyl) methylphosphonothioate.Analysis.'lheory: 8.1% P, 8.3% S 3.6% N. Found: 8.0% P, 8.5% S, 3.4% N.

EXAMPLE VIII Employing the procedure of Example VII but replacingO-(n-hexyl) methylphosphonochloridothionate wlth' an equimolecularamount of O-isoamyl ethylphosphonochloridoth-ionate there is obtainedO-isoamyl O-(3-trifluoromethyl-4-nitrophenyl) ethylphosphonothioatewhich is insoluble in water.

phonochloridothionate there is obtained O-(n-propy-l) O- (3'tri-fluoromethyl-4-nitrophenyl) phenylphosphonothio a-te.

EXAMPLE XI To a suitable reaction vessel equipped with a thermorrieter,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 12.4 parts by weight (substantially0.06 mole) of 3trifluoromethyl-4-nitrophenol, approximately 6.6 parts byweight (substantially 0.065 mole) of triethylamine, and approximately12.4 parts by weight (substantially 0.06 mole) of O-ethylethylphosphonochloridothionate. While agitating the mixture is heated upto the reflux temperature and then refluxed for 5 hours. The reactionmass is then cooled to room temperature and then quenched with water.The organic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so-washed solution is then strippedof volatiles under vacuum. The residue, an oil, is O-ethyl 0-(3-trifluoromethyl-4-nitrophenyl) ethylphosphonothioate.Analysis-Theory: 9.0% P, 4.1% N, 9.3% S. Found: 8.9% P, 4.0% N, 8.9% S.

EXAMPLE XII 4-nitrophenyl) benzylphosphonothioate which is insoluble inwater.

EXAMPLE XIII To a suitable reaction vessel equipped with a thermometeragitator and reflux condenser is charged approximately 88 pnrts byweight of benzene, approximately 10.4 parts by weight (substantially0.05 mole) of 3-trifluoromethyl-4-nitrophenol, approximately 5.1 partsby weight (substantially 0.05 mole) of triethylamine, and approximately9.4 parts by weight (substantially 0.05 mole) of O-isobutylmethylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for 6 hours. The reactionmass is then cooled to room temperature and then quenched with water.The organic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so-washed solution is then strippedof volatiles under vacuum. The residue, an oil, is O-isobutylO-(3-trifluoromethyl-4-nitrophenyl) methylphosphonothioate.Analysis.'1'heory: 8.7% P, 9.0% S, 3.9% N. Found: 8.9% P, 9.1% S, 4.0%N. I

EXAMPLE xiv Employing the procedure of Example XI-II but replacingO-isobutyl methylphosphonochloridothionate with an equimolecular amountof O-phenyl n-butylphosphonochloridothionate there is obtained O-phenylO-(B-trifluoromethyl-4-nitrophenyl) n-butylphosphonothioate which isinsoluble in water.

EXAMPLE XV To a suitablle reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byWeight of benzene, approxi mately 12.4 parts by weight (substantially0.06 mole) of 3-trifluoromethyl-4-nitrophenol, approximately 6.1 partsory: 9.1% P, 4.1% N, 9.3% S. Found: 9.0% P, 3.9%

EXAMPLE XVI Employing the procedure of Example XV but replacingO-(n-propyl) methylphosphonochloridothionate with an'equimolecularamount of O-methyl n-propylphosphonochloridothionate there is obtainedO-methyl O -(3' trifluoromethyl-4-nitrophenyl) n-propylphosphonothioatewhich is water-insoluble.

EXAMPLE xvrr f To a suitable reaction vessel equipped with athermometer, agitator and reflux condenser is charged approximately 88parts by weight of benzene, approximately 10.1 parts by weight(substantially 0.05 mole) of 3-trifiuoromethyl-4-nitrophenol,approximately 5,1 parts by weight (substantially 0.05 mole) of -triethylamine, and approximately 10.4 parts by weight (substantially 0.05mole) of O-(n-amyl) methylphosphonochloridothionate. While agitating themixture is .heated up to the reflux temperature and then refluxed for 6hours. The reaction mass is then cooled to.room temperature and thenquenched with water. The organic layer is separated and washed firstwith aqueous 3% sodium carbonate and then with water. The so-washedsolution is then stripped of volatiles under vacuum. The residue, anoil, is O-(n-amyl) O-(3-trifluoromethyl-4-nitrophenyl)methylphosphonothioate. Analysis.-Theory: 8.4% P, 8.6% S, 3.8% N. Found:8.5% P, 8.4% S, 3.5% N.

EXAMPLE XVIII 7 EXAMPLE xrx To a suitable reaction vessel equipped witha thermometer, agitator and reflux condenser is charged ap proximately88 parts by weight of benzene, approxi mately 10.4 parts by weight(substantially 0.05 mole) of v3-trifluoromethyl-4-nitrophenol,

the reflux temperature and then refluxed for 5 hours. The reaction massis then cooled to room temperature and then quenched with water. Theorganic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so-washed solution is then strippedof volatiles under vacuum. The residue, an oil, is O-(n-butyl)O-(3-trifluoromethyl-4-nitrophenyl) ethylphosphonothioate.

EXAMPLE xx mEmploying the procedure of Example XIX but replacingO-(n-butyl) ethylphosphonochloridothionate with an equimolar amount ofO-(n-propyl) cyclohexylphosphonoohloridothionate there is obtainedO-(n-propyl) O (3 trifluoromethyl '4 nitrophenyl)cyclohexylphosphonothioate.

EXAMPLE XXI To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 10.4 parts by weight (substantially0.05 mole) of 3-trifluoromethyl-4-nitrophenol, approximately 5.1 partsby weight (substantially 0.05 mole) of: triethylamine, and approximtaely10.3 parts by weight (substantially 0.05

mole) of O-phenyl met-hylphosphonochloridothionate..

While agitating the mixture is heated up to the reflux temperature andthen refluxed for 6 hours. The reaction mass is then cooled to roomtemperature and then quenched with water. The organic layer is separatedand washed first with aqueous 3% sodium carbonate and then with water.The so-washed solution is then stripped of volatiles under vacuum. Theresidue, an

approximately 6.1 parts by weight (substantially 0.06 mole) oftriethylamine, and approximately 10.0 par-ts by weight (substanoil, isO-phenyl O-(3-trifuoromethyl-4-nitrophenyl) met-hylphosphonothioate.Analysis.-'Iheory: 8.2% P, 8.5% S, 3.7% N. Found 8.2% P, S, 3.6% N.

EXAMPLE XXII To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 132 parts byweight of benzene, approximately 12.6

. parts by weight (substantially 0.06 mole) of3-trifluoromethyl-4-nitrophenol, approximately 6.2 pants by weight(substantially 0.06 mole) of triethylamine, and approximately 13.1 partsby weight (substantially 0.06 mole) of O-ethylphenylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for-6 hours. The reactionmass is then cooled to room temperature and then quenched with water.The organic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so-washed solution is then strippedof volatiles under vacuum. The residue, an oil, is O-ethylO-(3-triflu0ro- 4-methylphenyl) phenylphosphonothioate. Analysis-Theory: 7.9% P, 8.2% S, 3.6% N. Found: 7.8% P, 8.6% S, 3.6% N.

. EXAMPLE XXIII EXAMPLE XXIV To a suitable reaction vessel equipped witha thermometer, agitator and reflux condenser is charged approximately 88parts by weight of benzene, approximately 12.4 parts by weight(substantially 0.06 mole) of Z-trifluoromethyll-nitrophenol,approximately 6.1 parts by weight (substantially 0.06 mole) oftriethylamine, and approximately 9.5 parts by weight (substantially 0.06mole) of O-ethyl methylphosphonochloridothionate. While agitating themixture is heated up to the reflux temperature and then refluxed forhours. The reaction mass is then cooled to room temperature and thenquenched with water. The organic layer is separated and washed firstwith aqueous 3% sodium carbonate and then with water. The "so-washedsolution is then stripped of volatiles under vacuum. The residue isO-ethyl O-(2-trifluoromethyl-4- nitrophenyl) methylphosphonothioate.

EXAMPLE xxv To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 88 parts byweight of benzene, approximately 12.4 parts by weight(substantially 0.06mole) of S-trifluoromethyl- S-nitrophenol, approximately 6.1 parts byweight (substantially 0.06 mole) of triethylamine, and approximately 9.5parts by weight (substantially 0.06 mole) of O-ethylmethylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for 5 hours. The reactionmass is \then cooled to room temperature and then quenched with water.The organic layer is separated and washed first with aqueous 3% sodiumcarbonate and then with water. The so washed solution is then strippedof volatiles under vacuum. The residue is O-ethyl O-(5trifluoromethyl-3-nitrophenyl) methylphosphonothioate.

EXAMPLE XXV-I To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged approximately 88 parts byweight of benzene, approximately 12.9 parts by weight of2,4-dinitro-5-trifluoromethylphenol, approximately 6.1 parts by weightof triethylamine, and approximately 9.5 parts by weight of O-ethylmethylphosphonochloridothionate. While agitating the mixture is heatedup to the reflux temperature and then refluxed for 5 hours. perature andthen quenched with water. The organic layer is separated and washedfirst with aqueous 3% sodium carbonate and then with water. Theso-washed solution is then stripped of volatiles under vacuum. Theresidue is O-ethyl O-(2,4-dinitro-S-trifluoromethylphenyl)methylphosphonothioate.

EXAMPLE Xxvn Employing the procedure of Example XXII but replacingO-ethyl phenylphosphonochloridothionate with an equimolecular amount ofO-ethyl 'benzylphosphonochloridothionate there is obtained O-ethylO-(S-trifluoromethy1-4-nitrophenyl) benzylphosphonothioate which isinsoluble in water.

The methods by which the phosphonothioates of this invention areisolated will vary slightly with the reactants employed and the productproduced. Further purification by selective solvent extraction or byabsorptive agents such as activated carbon or clays can precede theremoval of the inert organic liquid or solvent when such is employed.Additionally an inert organic solvent can be added to and in thepurification by absorptive agents. However, the product is generallysatisfactory for insecticidal purposes without further purification.

Of the phosphonothioates of this invention a particularly useful groupare those of the formula ROS wherein R is phenyl (i.e. CQH5) or an alkylradical containing from 1 to 4 carbon atoms and wherein R is analiphatic hydrocarbon radical containing from 1 to 5 carbon atoms, thealpha-carbon of said R having two by- The reaction mass is then cooledto room temdrogen substituents (i.e. primary carbon, CH Of this groupthose of the formula wherein m is a whole number from 1 to 2 and whereinR is a primary alkyl radical containing from 2 to 4 carbon atoms areparticularly desirable.

It will be understood that the terms insect and insecticide are usedherein in their broad common usage to include spiders, mites, ticks, andlike pests which are not in the strict biological sense classed asinsects. Thus the usage herein conforms to the definitions provided byCongress in Public Law 104, the Federal Insecticide, Fungicide, andRodenticide Act" of 1947, Section 2, subsection h, wherein the terminsect is used to refer not only to those small invertebrate animalsbelonging mostly to the class Insecta, comprising six-legged, usuallywinged forms, as beetles, bugs, bees, flies, and so forth, but also toother allied classes of arthropods whose members are Wingless andusually have more than six legs, as spiders, mites, ticks,.centipedes,and wood lice.

The phosphonothioates of this invention are effective against a widevariety of insect pests. As illustrative of their activity but notlirnitative thereof is the following:

Contact Activity A rimless, 25 x 200 min. culture tube is rinsed withacetone and is placed in a holding block. The tube is filled with 70 cc.of distilled water. Next 0.1 cc. of liquid or 0.1 gr. of solid testchemical is dissolved in acetone to make a 1% by weight concentrate ofthe test chemical. 0.07 ml. of this concentrate is pipetted into theculture tube containing the distilled water. The tube is then stopperedwith an acetone washed rubber stopper and shaken vigorously tofacilitate complete mixing. Approximately 25 early fourth instar yellowfever mosquito larvae (Aedes aegypti) are transferred to the tube withthe aid of a pipette. The larvae are held in the test tube at roomtemperature for 24 hours at which time mortality observations are taken.This procedure is repeated at decreasing concentrations and a lowconcentration giving 100% mortality determined. The following resultswere obtained:

Test Chemical Cone. giving 100% Mortality in p.p.m.

1 This concentration gave an mortality.

Activity on Insect Body A 1% by weight concentrate of the test chemicalis prepared by dissolving the chemical in 10 ml. of acetone. A 0.25 cc.tuberculin, B.-D. Yale syringe is filled with the concentrate and placedin a microinjection apparatus. The injector lever is pressed severaltimes to make certain that no air bubbles are trapped in the needle andthe needle is wipedwith filter paper to remove any excess solution. Theinjector lever is pressed once to produce one microliter which isapplied directly to the ventral side of the abdomen of each of 10 plumCurculio, Conatrachelus nenuphar. After applicatiomeach insect isreleased-within observation dishes and held for 24 'hours at roomtemperature and mortality observations made at the end of that time.'This procedure is repeated at 'decreasing concentrations and thepercent mortality at certain low concentrations determined. Thefollowing results were obtained:

may be molecular in size and held in true solution in a suitable organicsolvent. It means further, that the particles may be colloidal in sizeand distributed throughout a liquid phase in the form of suspensions oremulsions or in the form of particles held in suspension by wettingagents. It also includes particles which are distributed in a semi-solidviscous carrier such as petrolatum or soap or other ointment base inwhich they may be actually dissolved in the semi-solid or held insuspension in the semi-solid with the aid of suitable wetting oremulsifying agents. The term dispersed also means that the particles maybe mixed with and distributed throughout a solid carrier providing amixture in particulate form, e.g. pellets, granules, powders, or dusts.The term dispersed also includes mixtures which are suitable for use asaerosols including solutions, suspensions, or emulsions ofthephosphonothioates of this invention in a carrier such asdichloro-difiuoromethane and the like fluoro chloroalkanes which boilbelow room temperature at atmospheric pressure.

In the instant specification and appended claims it is to be understoodthat the expression extending agent includes any and all of thosesubstances in which the phosphonothioates of this invention aredispersed. It includes, therefore, the solvents of a true solution, theliquid phase of suspensions, emulsions or aerosols, the semisolidcarrier of ointments and the solid phase of particulate solids,e.g. pellets, granules, dusts and powders.

Test Chemical Activity 0 Fa R0 8 0 -N0, Gone. in Mortality, percent bypercent R weight Insect Feeding Activity the test chemical in 10 m1. ofacetone. A 0.25 cc. tuberculin, B.-D. Yale syringe is filled with thisconcentrate and placed in a microinjection apparatus. The injector leveris pressed several times to make certain no air bubbles are trapped inthe needle and the needle is wiped with filter paper to remove excesssolution. The injector lever is pressed once to produce one microliterwhich is applied directly to each of 12 lima bean leaf discs 0.25 inchin diameter. Single second instar southern armyworm larvate (Prodeniaeridania) are placed on each disc and the disc encaged with a plasticcap. After 48 hours at room temperature mortality observations are made.This procedure is repeated at decreasing concentrations and the percentmortality at certain low concentrations determined. The results were asfollows:

Test Chemical Activity C F 7 R0 8 H Gone. in Mortality, P- O N 0 percentby percent weight R! methyl n-butyl- 0. 063 100 D cyclohexyl 0. 063 80yl 0. 25 90 0. 25 100 0.063 100 0.06 100 0. 06 100 0.02 80 0. 2 100 0.06 100 Although the phosphonothioates of this invention are The exactconcentration of the phosphonothioates of this invention employed incombatting or controlling insect pests can vary considerably providedthe required dosage '(i.e. toxic or lethal amount) thereof is suppliedto the pests or to the environment of the pests. When the extendingagent is a liquid or mixture of liquids (e.g. as in solutions,suspensions, emulsions, or aerosols) the concentration of thephosphonothioate employed to weight. turer must supply the agriculturistwith a low-cost conuseful per se in controlling a wide variety of insectpests,

it is preferable that they be supplied to the pests or to theenvironment of the pest or pests in a dispersed form in a suitableextending agent.

In the instant specification and appended claims it is to be understoodthat the term dispersed is used in its widest possible sense. When itissaid that the phosphonothioates of this invention are dispersed, itmeans that particles of the phosphonothioates of this invention supplythe desired dosage generally will be in the range of 0.001 to 50 percentby weight. When the extending agent is a semi-solid or solid, theconcentration of the phosphonothioate employed to supply the desireddosage generally will be in the range of 0.1 to 25 percent by From apractical point of view, the manufaccentrate or spray base orparticulate solid base in such form that, by merely mixing with water orsolid extender (e.g. powdered clay or talc) or other low-cost materialavailable to the agriculturist at the point of use, he will have aneasily prepared insecticidal spray or particulate solid. In such aconcentrate composition, the phosphonothioate generally will be presentin a concentration of 5 to 95- percent by weight, the residue being anyone or more of the well known insecticidal adjuv-ants, such as thevarious surface active agents (e.g. detergents, a soap or otheremulsifying or wetting agent), surface-active clays, solvents, diluents,carriermedia, adhesives, spreading agents, humectants, and the like.

These are a large number of organic liquids which can be used for thepreparation of solutions, suspensions or emulsions of thephosphonothioates of this invention. For example, isopropyl ether,acetone, methyl ethyl ketone, dioxane, cyclohexanone, carbontetrachloride, ethylene dichloride, tetrachloroethane, hexane, heptaneand like higher liquid alkanes, hydrogenated naphthalenes, solventnaphtha, benzene, toluene, xylene, petroleum fractions (e.g. thoseboiling almost entirely under 400 F. at atmospheric pressure and havinga flash point above about 80 F., particularly kerosene), mineral oilshaving an unsulfonatable residue above about '80 percent and preferablyabove about percent. In those instances wherein. there may be concernabout the phytotoxicity of the organic liquid extending agent a portionof same can be replaced by such low molecular weight aliphatichydrocarbons as dipentene, diisobutylene, propylene trimer, and the likeor suitable polar organic liquids such as the aliphatic ethers and thealiphatic ketones containing not more than about carbon atoms asexemplified by acetone, methyl ethyl ketone, diisobutyl ketone, dioxane,isopropyl ether, and the like. In certain instances, it is advantageousto employ a mixture of organic liquids as the extending agent.

When the phosphonothioates of this invention are to be supplied to theinsect pests or to the environment of the pests as aerosols, it isconvenient to dissolve them in a suitable solvent and disperse theresulting solution in dichlorodifluoromethane or like chlorofluoroalkanewhich boils below room temperature at atmospheric pressure.

The phosphonothioates of this invention are preferably supplied to theinsect pests or to the environment of the insect pests in the form ofemulsions or suspensions. Emulsions or suspensions are prepared bydispersing the phosphonothioate of this invention either per se or inthe form of an organic solution thereof in water with the aid of awater-soluble surfactant. The term surfactant as employed here and inthe appended claims is used as in volume II of Schwartz, Perry, andBerchs Surface Active Agents and Detergents (1958, IntersciencePublishers, Inc., New York) in place of the expression emulsifyingagent" to connote generically the various emulsifying agents, dispersingagents,

wetting agents and spreading agents that are adapted to be admixed withthe active compounds of this invention in order to secure better wettingand spreading of the active ingredients in the water vehicle or carrierin which they are insoluble through lowering the surface tension of thewater (see also Frear, Chemistry of Insecticides, Fungicides andHerbicides, second edition, page 280). These surfactants include thewell-known capillary-active substances which may be anion-active (oranionic), cation active (or cationic), or non-ionizing (or non-ionic)which are described in detail in volumes I and II of Schwartz, Perry,and Berchs Surface Active Agents and Detergents" (1958, IntersciencePublishers, Inc., New York) and also in the November 1947 issue ofChemical Industries (pages 811-824) in an article entitled SyntheticDetergents, by John W. Mc- Cutcheon, and also in the July, August,September and October 1952 issues of Soap and Sanitary Chemicals underthe title Synthetic Detergents." The disclosures of these articles withrespect to surfactants, i.e. the anion- ;active, cation-active and thenon-ionizing capillary ac-- tive substances, are incorporated in thisspecification by reference in order to avoid unnecessary enlargement ofthis specification. The preferred surfactants are the water-solubleanionic surface-active agents and the water soluble non-ionicsurface-active agents set forth in US. 2,846,398 (issued August 5,1958). In general it is preferred that a mixture of water-solubleanionic and water-soluble non-ionic surfactants be employed.

The phosphonothioates of this invention can be dis persed by suitablemethods (e.g. tumbling or grinding) in solid extending agents either oforganic or inorganic nature and supplied to the insect pests environmentin particulate form. Such solid materials include for example,tricalcium phosphate, calcium carbonate, kaolin, bole, kieselguhr, talc,bentonite, fullers earth, pyrophillite, diatomaceous earth, calcinedmagnesia, volcanic ash, sulfur and the like inorganic solid materials,and include for example, such materials of organic nature as powderedcork, powdered wood, and powdered walnut shells. The preferred solidcarriers are the adsorbent clays, e.g. bentonite. These mixtures can beused for insecticidal purposes in the dry form, or,- by addition ofwater-soluble surfactants or wetting agents the dry particulate solidscan be rendered wettable by water so as to obtain stable aqueousdispersions or suspensions suitable for use as sprays.

I the phosphonothioates of this invention.

12 invention can be dispersed in a semi-solid extending agent such aspetrolatum or soap (e.g. sodium stearate or oleate or palmitate ormixtures thereof) with or without the aid of solubility promotors and/or surfactants or dispersing agents.

In all of the forms described above the dispersions can be providedready for use in combatting insect pests or they can be provided in aconcentrated form suitable 'for mixing with or dispersing in otherextending agents.

As illustrative of a particularly useful concentrate is an intimatemixture of phosfihonothioate of this invention with a water-solublesurfactant which lowers the surface tension of water in the weightproportions of 0.1 to 15 parts of surfactant with sufficient of thephosphonothioate of this invention to make 100 parts by weight. Such aconcentrate is particularly adapted to be made into a spray forcombatting various forms of insect pests by the addition of waterthereto. As illustrative of such a concentrate is an intimate mixture ofparts by weight of O-(n-butyl) O-(3-trifluoromethyl-4-nitrophenyl)methylphosphonothioate and 5 parts by weight of a watersoluble non-ionicsurfactant such as the polyoxyethylene derivative of sorbitanmonolaurate.

Another useful concentrate adapted 'to be made into a spray forcombatting a variety of insect pests is a solution (preferably asconcentrated as possible) of a phosphonothioate of this invention in anorganic solvent therefor. The said liquid concentrate preferablycontains dissolved therein a minor amount (e.g. 0.5 to 10 percent byweight of the new insecticidal agent) of a surfactant (or emulsifyingagent), which surfactant is also water-soluble. As illustrative of sucha concentrate is a solution of O- (n-propyl)O-(3-trifluoromethyl-4-nitrophenyl) methylphosphonothioate in benzenewhich solution contains dissolved therein a water-solublepolyoxyethylene glycol non-ionic surfactant and a water-solublealkylaryl sulfonate anionic surfactant.

Of the surfactants aforementioned in preparing the various emulsifiers,wettable or dispersible compositions or concentrates of this invention,the anionic and noncontain 15 to 30 moles of ethylene oxide per mole of"the hexitol anhydride or the alkylphenol.

In all of the various dispersions described hereinbefore forinsecticidal purposes, the active ingredient can be one or more of thecompounds of this invention. The compounds of this invention can also beadvantageously employed in combination with other pesticides,,includingfor example, nematocides, bactericides, and herbicides. In this mannerit is possible to obtain mixtures which are effective against a widevariety of pests and other forms of noxious life.

In controlling or combatting insect pests the phosphonothioates ofthisinvention either per se or compositions comprising same are suppliedto the insect pests or to their environment in a lethal or toxic amount.This can be done by dispersing the new insecticidal agent orinsecticidal composition. comprising same in, on or over an infestedenvironment or in, on or over an environment the insect pests frequent,e.g. agricultural soil or other growth media or other media infestedwith insect pests or attractable to the pests for habitational orsustenance or propagational purposes, in any conventional fashion whichpermits contact between the insect pests and Such dispersing can bebrought about by applying sprays or particulate solid compositions to asurface infested with the insect pests or attractable to the pests, asforexample, the surface of an agricultural soil or other media such asthe above ground surface of plants by any of the conventional methods,e.g. power dusters,'boom and hand sprayers, and spray dusters. Also forsub-surface application such dispersing can be carried out by simplymixing the new insecticidal agent per se or insecticidal spray orparticulatesolid compositions comprising same with the infestedenvironment or with the environment the insect pests frequent, or byemploying a liquid carrier for the new insecticidal agent to accomplishsub-surface penetration and impregnation therein.

While this invention has been described with respect to certainembodiments, it is to be understood that it is not so limited and thatvariations and modifications thereof obvious to those skilled in the artcan be made,

without departing from the spirit and scope thereof.

What is claimed is: 1. An O-(aryl) phosphonothioate of the formulawherein m and n are whole numbers from 1 to 2 and wherein the sum of mand n is a whole number from 2 to 3, wherein R is a hydrocarbyl radicalcontaining from 1 to 8 carbon atoms and which is freeof olefinic andacetylenic unsaturation, and wherein R is a hydrocarbon radicalcontaining 1 to 8 carbon atoms.

2. An O-(4-nitro 3 trifluoromethyl phenyl) phosphonothioate of theformula P-O N02 1 wherein R' is an alkyl radical containing from 1 to 4carbon atoms, and wherein R is an aliphatic hydrocarbon radicalcontaining from 1 to 5 carbon atoms, the alphacarbon of said R havingtwo hydrogen substituents.

3. An O-(4-nitro 3 trifiuoromethylphenyl) phosphonothioate of theformula no-g-oQ-No. I

(CH:)mH

wherein m and n are whole numbers from 1 to 2 and wherein the sum of mand n is a whole number from 2 to 3 with no s lLz wherein Z is a halogenof atomic number in the range of 9. The method which comprises reacting4-nitro-3-tri-- fluoromethylphenol with wherein R' is an alkyl radicalcontaining 1 to 4 carbon atoms and wherein R is an aliphatic hydrocarbonradical containing from 1 to 5 carbon atoms, the alpha-carbon of said Rcontainingtwo hydrogen substituents, in the presence of a hydrogenchloride scavenging agent.

10. The method which comprises reacting 4-nitro-3-trifluoromethylphenolwith said concentrate forming an emulsion with water upon i no-r-olwherein m is a whole number from 1 to 2 and wherein R is an alkylradical containing from 2 to 4 .carbon atoms, thealpha-carbon atom ofsaid R containing two hydrogen substituents.

11. An insecticidal composition comprising a compound of claim 1dispersed in an extending agent.

12. An insegticidal composition comprising a compound of claim 1dispersed in an extending agent selected from the group consisting ofsolid and semi-solid extending agents, the composition containing 0.1 to25 percent by weight of said compound of claim 1.

13. An insecticidal composition comprising a compound of claim 1dispersed in a liquid extending agent, the composition containing 0.001to 50 percent by weight of said compound of claim 1.

14. An insecticidal concentrate comprising a compound of claim 2 and aninsecticidal adjuvant, said concentrate containing from 5 to percent byweight of thecompound of claim 2.

15. An insecticidal concentrate comprising a compound of claim 2dispersed in an organic solvent therefor and having dissolved therein aminor amount of a surfactant,

agitation therewith.

16. An insecticidal concentrate adaptedto be made into a sprayablecomposition by the addition of water comprising -a compound of claim 2in admixture with a water-soluble surfactant in the weight proportion of0.1 to 15 parts of surfactant and sufficient of said compound of claim 2to make parts by weight.

17. The method of controlling insects which comprises contacting theinsects with a toxic amount of at least one compound of claim 1.

18. The method for protection of plants against insect attack whichcomprises applying to the plant an insecticidal amount of at least onecompound of claim 1'.

19. The method of controlling insects which comprises contacting theinsects with a toxic amount of at least one compound of claim 2.-

20. The method for protection of plants against insect attack whichcomprises applying to the plant an insecticidal amount of at least onecompound of claim 2.

References Cited in the file of this patent UNITED STATES PATENTS

1. AN O-(ARYL) PHOSPHONOTHIOATE OF THE FORMULA